Daidzein at a glance

  • A type of antioxidant known as an isoflavone found in soybeans
  • Pronounced ability to help skin better withstand environmental exposure
  • Improves signs of ageing and texture changes coinciding with estrogen decline
  • Helps improve skin’s natural content of hyaluronic acid

Daidzein description

Daidzein is one of the primary isoflavone antioxidants found naturally in soy, although lesser amounts occur in other foods such as nuts, grapes, and cabbage. Research on human skin has shown it helps mitigate the cascade of oxidative and other damage triggered by exposure to UVB light. Indeed, one study showed daidzein reduced this damage by 71%! This also makes it a good soothing ingredient since it helps offset the multi-layer irritation UV light causes. This soy isoflavone has been shown to have protective benefits for skin’s underlying support, helping to maintain the look and feel of youthful firmness instead of leaving age-related deterioration unchecked. Daidzein is absorbed well, but research has shown its “sister” isoflavone genistein has better absorption; however, studies have also shown that combining daidzein and genistein offers greater benefits due to their natural affinity for skin and the distinctive benefits each provides. Research has also shown daidzein is more effective topically when formulated in a skin-friendly delivery system such as complex sugars known as cyclodextrins. Daidzein is considered safe and non-irritating as used in skin care, where amounts range from 0.02%–0.5% when used in pure form (rather than what naturally occurs in soy extracts).  

Daidzein references

  • Phytotherapy Research, March 2020, pages 435–447
  • Journal of Drug Delivery Science and Technology, June 2019, pages 63–69
  • Molecules, December 2017, pages 1–11
  • Australasian Journal of Dermatology, February 2015, pages e7–e14
  • International Journal of Pharmaceutics, August 2008, pages 36–44

Peer-reviewed, substantiated scientific research is used to assess ingredients in this dictionary. Regulations regarding constraints, permitted concentration levels and availability vary by country and region.

Ingredient ratings


Proven and supported by independent studies. Outstanding active ingredient for most skin types or concerns.


Necessary to improve a formula's texture, stability, or penetration.


Generally non-irritating but may have aesthetic, stability, or other issues that limit its usefulness.


There is a likelihood of irritation. Risk increases when combined with other problematic ingredients.


May cause irritation, inflammation, dryness, etc. May offer benefit in some capability but overall, proven to do more harm than good.


We couldn't find this in our ingredient dictionary. We log all missing ingredients and make continuous updates.

Not rated